A wide variety of different types of cables are utilized to transmit power and/or communications signals. In certain applications, it is desirable to provide a moisture barrier in order to provide protection to internal components of a cable. For example, in cables containing one or more optical fibers, a moisture barrier is typically provided to reduce moisture penetration that can weaken or destroy the fibers. In a typical implementation, an optical fiber cable includes a sheath, such as a buffer tube, that provides protection to optical fibers situated therein, and a moisture barrier is incorporated into the buffer tube. Different types of moisture barriers have been utilized in association with conventional optical fiber cables. One conventional technique is to fill a cable or buffer tube with a fluid or a gel intended to block moisture incursion and to absorb mechanical shock; however, such fluids and gels are typically messy and difficult to process in both a manufacturing environment and during field service operations. Other conventional techniques include the placement of water absorbent chemicals into the cable. In some approaches, the water absorbent chemicals can be mixed with a fluid or gel; however, the mixture suffers from the same drawbacks as those discussed above for the fluid or gel.
In other cases, water absorbent materials are applied to the surface of a tape, yarn, or other substrate that is inserted into the cable, for example, in an essentially lengthwise or helical manner. Tapes can be made of materials such as polyester, polyolefin, metal, composite, or foamed elastomer. The tape or yarn functions as a transport medium for water absorbent or water swellable materials. However, currently available tapes and yarns often include materials that increase overall tensile strength and facilitate application of the tapes or yarns. As a result, these tapes and yarns add additional cost and size (e.g., diameter) to cables, often have limitations in processing length, and create material handling issues. Additionally, a tape or yarn is typically required to be incorporated along the full length of a cable during assembly. Accordingly, there is an opportunity for improved water-resistant optic fiber cables and associated techniques for forming water-resistant optical fiber cables.